[en] Structure factors and total scattering intensities are calculated for a gas of hard discs assumed to have a uniform electron density using an eight-term series in the Percus-Yevick approximation. The convergence of the series in the long wavelength limit is discussed briefly. The relevance of the calculations to some two-dimensional liquid-like situations is mentioned. In particular, it is proposed that the results can be used to interpret the diffuse X-ray scattering produced by the fibrous protein, elastoidin. (author)